The Larch Sanctuary is a 59 acre part of the Whitmud Ravine located on the south side of 23rd Avenue. The combination of coniferous, deciduous, and mixed woods forests provide habitat for dozens of species of mammals and birds, including our largest woodpecker, the pileated woodpecker. Moose, deer, coyote, fox and other small mammals find a home here. Snags provide nest sites for cavity nesting species, shoreline vegetation lines the creek forming sensitive riparian areas, and Edmonton’s only ox bow lake provides important habitat for aquatic species, amphibians, and waterfowl. An oxbow lake is a U-shaped lake that forms when a wide meander of a river is cut off, creating a free-standing body of water. This land form is so named for its distinctive curved shape, which resembles the bow pin of an oxbow. Last time I visited the ox bow lake in the Larch Sanctuary was in the summer and at that point the muskrats were having a ball swimming back and forth across the lake. At this time of the year the lake is considerable quieter, yet still very beautiful in its frozen state.
The very first bird we spotted as we arrived at the oxbow pond down at the Whitemud ravine was a male mallard that was snoozing on a log. The log was covered in lush greenery with the mallard cosy like a bug in a rug in the greenery. It was very idyllic and looked quite comfortable. Oxbow ponds are unique habitats where the water is still and stagnant compared to the rushing water in the creek. There are rumours of numerous oxbow ponds along the Whitemud creek. So far I have found two, both almost entirely covered with thick riparian vegetation making them surprisingly difficult to spot although they are only steps away from the trail. This particular oxbow is the largest one I have found so far and is bound by an old beaver dam at the north end and a wall of accreted sediments on the south end. Groundwater and seepage from the west side of the ravine feeds the oxbow, as does spring and surface runoff. Other than seasonal fluctuations in the water level the water is completely still in these pond.
It has been raining over the last few days, but this morning there was a break in the weather so without further ado, we went down to the Whitemud Creek to check out what we could find. On a whim we decided to take the trail along going south along the Whitemud Creek from Snow Valley. Usually we stick to the northern section, but I have been curious for a while now to check out some oxbow ponds in the southern section. Right off the bat we saw a subtle movement along the water’s edge. Something tiny and well-camouflaged was scurrying around on the muddy bank. A closer look revealed that it was a small shore bird that was definitely a lifer. After a bit of studying Merlin and discussions back and forth we reached a unanimous verdict, it was a Spotted Sandpiper (Actitis macularius, Lifer #162, AB Big Year #114). The identification was unmistakable, the spotted under parts, orange bill and bobbing tail as it walked around along the water’s edge. That was a great start to a pleasant morning nature walk. The sandpiper was a welcomed bonus, but the real reason we went to this part of the creek were the oxbows. We did find two oxbow ponds nestled among the vegetation along the trail. We did not have the time to explore them today, but now that I know where they are I am looking forward to coming back and spend some more quality time exploring them. Todays picture shows a wide meander in the Whitemud Creek, this is how oxbow ponds are formed. When a river or creek creates a wide meander like this neck of the meander progressively becomes narrower until it is only a land bridge. Sooner or later the river cuts through the neck, e.g. during high water flow regimes during the spring melt, cutting off the meander and forming an oxbow lake. Oxbow lakes are U-shaped and become free-standing bodies of water with very little or not flow and provide a unique habitat quite different from the habitats along the fast flowing water in the main creek.